Method for triggering a buffer status reporting in wireless communication system and a device therefor

ABSTRACT

The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for triggering a buffer status reporting in wireless communication system, the method comprising: configuring with a first SR resource configuration and a second SR resource configuration; checking whether or not data is a first data on logical channels mapped to the first SR resource configuration, when the data becomes available for a first logical channel mapped to the first SR resource configuration, in a state that the first logical channel has a lower priority than a highest priority among priorities of logical channels having data, which are mapped to the second SR resource configuration; and triggering a first BSR if the data is the first data on logical channels mapped to the first SR resource configuration.

This application is a National Stage Entry of International ApplicationNo. PCT/KR2018/005735 filed May 18, 2018, which claims the benefit ofU.S. Provisional Application No. 62/518,605 filed Jun. 13, 2017, all ofwhich are hereby incorporated by reference in their entirety for allpurposes as if fully set forth herein.

TECHNICAL FIELD

The present invention relates to a wireless communication system and,more particularly, to a method for triggering a buffer status reportingin wireless communication system and a device therefor.

BACKGROUND ART

As an example of a mobile communication system to which the presentinvention is applicable, a 3rd Generation Partnership Project LongTermEvolution (hereinafter, referred to as LTE) communication system isdescribed in brief.

FIG. 1 is a view schematically illustrating a network structure of anEvolved Universal Mobile Telecommunications System (E-UMTS) as anexemplary radio communication system. The E-UMTS is an advanced versionof a conventional Universal Mobile Telecommunications System (UMTS) andbasic standardization thereof is currently underway in the 3GPP. E-UMTSmay be generally referred to as a Long Term Evolution (LTE) system. Thecommunication network is widely deployed to provide a variety ofcommunication services such as voice (VoIP) through IMS and packet data.

Referring to FIG. 1, the E-UMTS includes a User Equipment (UE), eNode Bs(eNBs), and an Access Gateway (AG) which is located at an end of thenetwork (E-UTRAN) and connected to an external network. The eNBs maysimultaneously transmit multiple data streams for a broadcast service, amulticast service, and/or a unicast service.

One or more cells may exist per eNB. The cell is set to operate in oneof bandwidths such as 1.25, 2.5, 5, 10, 15, and 20 MHz and provides adownlink (DL) or uplink (UL) transmission service to a plurality of UEsin the bandwidth. Different cells may be set to provide differentbandwidths. The eNB controls data transmission or reception to and froma plurality of UEs. The eNB transmits DL scheduling information of DLdata to a corresponding UE so as to inform the UE of a time/frequencydomain in which the DL data is supposed to be transmitted, coding, adata size, and hybrid automatic repeat and request (HARQ)-relatedinformation. In addition, the eNB transmits UL scheduling information ofUL data to a corresponding UE so as to inform the UE of a time/frequencydomain which may be used by the UE, coding, a data size, andHARQ-related information. An interface for transmitting user traffic orcontrol traffic may be used between eNBs. A core network (CN) mayinclude the AG and a network node or the like for user registration ofUEs. The AG manages the mobility of a UE on a tracking area (TA) basis.One TA includes a plurality of cells.

Although wireless communication technology has been developed to LTE andNR based on wideband code division multiple access (WCDMA), the demandsand expectations of users and service providers are on the rise. Inaddition, considering other radio access technologies under development,new technological evolution is required to secure high competitivenessin the future. Decrease in cost per bit, increase in serviceavailability, flexible use of frequency bands, a simplified structure,an open interface, appropriate power consumption of UEs, and the likeare required.

As more and more communication devices demand larger communicationcapacity, there is a need for improved mobile broadband communicationcompared to existing RAT. Also, massive machine type communication(MTC), which provides various services by connecting many devices andobjects, is one of the major issues to be considered in the nextgeneration communication (NR, New Radio). In addition, a communicationsystem design considering a service/UE sensitive to reliability andlatency is being discussed. The introduction of next-generation RAT,which takes into account such Enhanced Mobile BroadBand (eMBB)transmission, and ultra-reliable and low latency communication (URLLC)transmission, is being discussed.

DISCLOSURE Technical Problem

An object of the present invention devised to solve the problem lies ina method and device for triggering and transmitting a buffer statusreporting in wireless communication system.

In the prior art, the UE triggers a regular BSR when UL data, for alogical channel which belongs to a LCG, becomes available fortransmission in the RLC entity or in the PDCP entity and either the databelongs to a logical channel with higher priority than the priorities ofthe logical channels which belong to any LCG and for which data isalready available for transmission, or there is no data available fortransmission for any of the logical channels which belong to a LCG. Ifthere is no UL resource for transmitting the regular BSR, the UEtriggers a SR.

The problem in the prior art is that the UE does not trigger a BSR whena data becomes available for a LCH that has a lower logical channelpriority than a LCH that already data available for transmission, evenif those two LCHs are mapped to different SR resource.

However, if considering that different SR resource is used forrequesting radio resource for different type of traffics, the UE needsto trigger a new BSR on a SR resource configuration when a first databecomes available for transmission on the SR resource, if a logicalchannel where the data receives has lower priority than priorities ofother logical channels.

On the other hand, if there is a pending SR in the SR resourceconfiguration, the UE no longer needs to trigger the SR in the same SRresource configuration, but according to the prior art, the UE maytrigger the SR in a certain situation. So, the BSR trigger mechanismconsidering only logical channel priority should be modified in an NRsituation where a separate numerology is mapped for each logicalchannel.

The technical problems solved by the present invention are not limitedto the above technical problems and those skilled in the art mayunderstand other technical problems from the following description.

Technical Solution

The object of the present invention can be achieved by providing amethod for User Equipment (UE) operating in a wireless communicationsystem as set forth in the appended claims.

In another aspect of the present invention, provided herein is acommunication apparatus as set forth in the appended claims.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

Advantageous Effects

The invention is that when a data becomes available for a logicalchannel and if it is the first data of a group of logical channels thatare mapped to a same SR resource, the UE triggers a regular BSR. Ifthere is no UL resource for transmitting the regular BSR, the UEtriggers a SR that is mapped to the logical channel where the databecomes available.

According to the present invention, when the UE has already highpriority data (e.g., URLLC), the UE can trigger a BSR for low prioritydata (e.g., eMBB) for obtaining another SR resource. And when there isany pending SR on a SR resource configuration, the UE may not need totrigger BSR on the same SR resource configuration, if the BSR furthertriggers SRs to avoid unnecessary waste of resources.

It will be appreciated by persons skilled in the art that the effectsachieved by the present invention are not limited to what has beenparticularly described hereinabove and other advantages of the presentinvention will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention.

FIG. 1 is a diagram showing a network structure of an Evolved UniversalMobile Telecommunications System (E-UMTS) as an example of a wirelesscommunication system;

FIG. 2a is a block diagram illustrating network structure of an evolveduniversal mobile telecommunication system (E-UMTS), and FIG. 2b is ablock diagram depicting architecture of a typical E-UTRAN and a typicalEPC;

FIG. 3 is a diagram showing a control plane and a user plane of a radiointerface protocol between a UE and an E-UTRAN based on a 3rd generationpartnership project (3GPP) radio access network standard;

FIG. 4a is a block diagram illustrating network structure of NG RadioAccess Network (NG-RAN) architecture, and FIG. 4b is a block diagramdepicting architecture of functional Split between NG-RAN and 5G CoreNetwork (5GC);

FIG. 5 is a diagram showing a control plane and a user plane of a radiointerface protocol between a UE and a NG-RAN based on a 3rd generationpartnership project (3GPP) radio access network standard;

FIG. 6 is a block diagram of a communication apparatus according to anembodiment of the present invention;

FIG. 7 is a diagram for Scheduling-request transmission;

FIG. 8 is a diagram for signaling of buffer status reporting via a MACCE;

FIG. 9 is an example of mapping between Logical Channel and Numerology;

FIG. 10 is a conceptual diagram for triggering and transmitting a bufferstatus reporting in wireless communication system according toembodiments of the present invention; and

FIG. 11 is an example for triggering and transmitting a buffer statusreporting in wireless communication system according to embodiments ofthe present invention.

BEST MODE

Universal mobile telecommunications system (UMTS) is a 3rd Generation(3G) asynchronous mobile communication system operating in wideband codedivision multiple access (WCDMA) based on European systems, globalsystem for mobile communications (GSM) and general packet radio services(GPRS). The long-term evolution (LTE) of UMTS is under discussion by the3rd generation partnership project (3GPP) that standardized UMTS.

The 3GPP LTE is a technology for enabling high-speed packetcommunications. Many schemes have been proposed for the LTE objectiveincluding those that aim to reduce user and provider costs, improveservice quality, and expand and improve coverage and system capacity.The 3G LTE requires reduced cost per bit, increased serviceavailability, flexible use of a frequency band, a simple structure, anopen interface, and adequate power consumption of a terminal as anupper-level requirement.

Hereinafter, structures, operations, and other features of the presentinvention will be readily understood from the embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings. Embodiments described later are examples in which technicalfeatures of the present invention are applied to a 3GPP system.

Although the embodiments of the present invention are described using along term evolution (LTE) system and a LTE-advanced (LTE-A) system inthe present specification, they are purely exemplary. Therefore, theembodiments of the present invention are applicable to any othercommunication system corresponding to the above definition. In addition,although the embodiments of the present invention are described based ona frequency division duplex (FDD) scheme in the present specification,the embodiments of the present invention may be easily modified andapplied to a half-duplex FDD (H-FDD) scheme or a time division duplex(TDD) scheme.

FIG. 2a is a block diagram illustrating network structure of an evolveduniversal mobile telecommunication system (E-UMTS). The E-UMTS may bealso referred to as an LTE system. The communication network is widelydeployed to provide a variety of communication services such as voice(VoIP) through IMS and packet data.

As illustrated in FIG. 2a , the E-UMTS network includes an evolved UMTSterrestrial radio access network (E-UTRAN), an Evolved Packet Core (EPC)and one or more user equipment. The E-UTRAN may include one or moreevolved NodeB (eNodeB) 20, and a plurality of user equipment (UE) 10 maybe located in one cell. One or more E-UTRAN mobility management entity(MME)/system architecture evolution (SAE) gateways 30 may be positionedat the end of the network and connected to an external network.

As used herein, “downlink” refers to communication from eNodeB 20 to UE10, and “uplink” refers to communication from the UE to an eNodeB. UE 10refers to communication equipment carried by a user and may be alsoreferred to as a mobile station (MS), a user terminal (UT), a subscriberstation (SS) or a wireless device.

FIG. 2b is a block diagram depicting architecture of a typical E-UTRANand a typical EPC.

As illustrated in FIG. 2b , an eNodeB 20 provides end points of a userplane and a control plane to the UE 10. MME/SAE gateway 30 provides anend point of a session and mobility management function for UE 10. TheeNodeB and MME/SAE gateway may be connected via an Si interface.

The eNodeB 20 is generally a fixed station that communicates with a UE10, and may also be referred to as a base station (BS) or an accesspoint. One eNodeB 20 may be deployed per cell. An interface fortransmitting user traffic or control traffic may be used between eNodeBs20.

The MME provides various functions including NAS signaling to eNodeBs20, NAS signaling security, AS Security control, Inter CN node signalingfor mobility between 3GPP access networks, Idle mode UE Reachability(including control and execution of paging retransmission), TrackingArea list management (for UE in idle and active mode), PDN GW andServing GW selection, MME selection for handovers with MME change, SGSNselection for handovers to 2G or 3G 3GPP access networks, Roaming,Authentication, Bearer management functions including dedicated bearerestablishment, Support for PWS (which includes ETWS and CMAS) messagetransmission. The SAE gateway host provides assorted functions includingPer-user based packet filtering (by e.g. deep packet inspection), LawfulInterception, UE IP address allocation, Transport level packet markingin the downlink, UL and DL service level charging, gating and rateenforcement, DL rate enforcement based on APN-AMBR. For clarity MME/SAEgateway 30 will be referred to herein simply as a “gateway,” but it isunderstood that this entity includes both an MME and an SAE gateway.

A plurality of nodes may be connected between eNodeB 20 and gateway 30via the S1 interface. The eNodeBs 20 may be connected to each other viaan X2 interface and neighboring eNodeBs may have a meshed networkstructure that has the X2 interface.

As illustrated, eNodeB 20 may perform functions of selection for gateway30, routing toward the gateway during a Radio Resource Control (RRC)activation, scheduling and transmitting of paging messages, schedulingand transmitting of Broadcast Channel (BCCH) information, dynamicallocation of resources to UEs 10 in both uplink and downlink,configuration and provisioning of eNodeB measurements, radio bearercontrol, radio admission control (RAC), and connection mobility controlin LTE_ACTIVE state. In the EPC, and as noted above, gateway 30 mayperform functions of paging origination, LTE-IDLE state management,ciphering of the user plane, System Architecture Evolution (SAE) bearercontrol, and ciphering and integrity protection of Non-Access Stratum(NAS) signaling.

The EPC includes a mobility management entity (MME), a serving-gateway(S-GW), and a packet data network-gateway (PDN-GW). The MME hasinformation about connections and capabilities of UEs, mainly for use inmanaging the mobility of the UEs. The S-GW is a gateway having theE-UTRAN as an end point, and the PDN-GW is a gateway having a packetdata network (PDN) as an end point.

FIG. 3 is a diagram showing a control plane and a user plane of a radiointerface protocol between a UE and an E-UTRAN based on a 3GPP radioaccess network standard. The control plane refers to a path used fortransmitting control messages used for managing a call between the UEand the E-UTRAN. The user plane refers to a path used for transmittingdata generated in an application layer, e.g., voice data or Internetpacket data.

A physical (PHY) layer of a first layer provides an information transferservice to a higher layer using a physical channel. The PHY layer isconnected to a medium access control (MAC) layer located on the higherlayer via a transport channel. Data is transported between the MAC layerand the PHY layer via the transport channel. Data is transported betweena physical layer of a transmitting side and a physical layer of areceiving side via physical channels. The physical channels use time andfrequency as radio resources. In detail, the physical channel ismodulated using an orthogonal frequency division multiple access (OFDMA)scheme in downlink and is modulated using a single carrier frequencydivision multiple access (SC-FDMA) scheme in uplink.

The MAC layer of a second layer provides a service to a radio linkcontrol (RLC) layer of a higher layer via a logical channel. The RLClayer of the second layer supports reliable data transmission. Afunction of the RLC layer may be implemented by a functional block ofthe MAC layer. A packet data convergence protocol (PDCP) layer of thesecond layer performs a header compression function to reduceunnecessary control information for efficient transmission of anInternet protocol (IP) packet such as an IP version 4 (IPv4) packet oran IP version 6 (IPv6) packet in a radio interface having a relativelysmall bandwidth.

A radio resource control (RRC) layer located at the bottom of a thirdlayer is defined only in the control plane. The RRC layer controlslogical channels, transport channels, and physical channels in relationto configuration, re-configuration, and release of radio bearers (RBs).An RB refers to a service that the second layer provides for datatransmission between the UE and the E-UTRAN. To this end, the RRC layerof the UE and the RRC layer of the E-UTRAN exchange RRC messages witheach other.

One cell of the eNB is set to operate in one of bandwidths such as 1.25,2.5, 5, 10, 15, and 20 MHz and provides a downlink or uplinktransmission service to a plurality of UEs in the bandwidth. Differentcells may be set to provide different bandwidths.

Downlink transport channels for transmission of data from the E-UTRAN tothe UE include a broadcast channel (BCH) for transmission of systeminformation, a paging channel (PCH) for transmission of paging messages,and a downlink shared channel (SCH) for transmission of user traffic orcontrol messages. Traffic or control messages of a downlink multicast orbroadcast service may be transmitted through the downlink SCH and mayalso be transmitted through a separate downlink multicast channel (MCH).

Uplink transport channels for transmission of data from the UE to theE-UTRAN include a random access channel (RACH) for transmission ofinitial control messages and an uplink SCH for transmission of usertraffic or control messages. Logical channels that are defined above thetransport channels and mapped to the transport channels include abroadcast control channel (BCCH), a paging control channel (PCCH), acommon control channel (CCCH), a multicast control channel (MCCH), and amulticast traffic channel (MTCH).

FIG. 4a is a block diagram illustrating network structure of NG RadioAccess Network (NG-RAN) architecture, and FIG. 4b is a block diagramdepicting architecture of functional Split between NG-RAN and 5G CoreNetwork (5GC).

An NG-RAN node is a gNB, providing NR user plane and control planeprotocol terminations towards the UE, or an ng-eNB, providing E-UTRAuser plane and control plane protocol terminations towards the UE.

The gNBs and ng-eNBs are interconnected with each other by means of theXn interface. The gNBs and ng-eNBs are also connected by means of the NGinterfaces to the 5GC, more specifically to the AMF (Access and MobilityManagement Function) by means of the NG-C interface and to the UPF (UserPlane Function) by means of the NG-U interface.

The Xn Interface includes Xn user plane (Xn-U), and Xn control plane(Xn-C). The Xn User plane (Xn-U) interface is defined between two NG-RANnodes. The transport network layer is built on IP transport and GTP-U isused on top of UDP/IP to carry the user plane PDUs. Xn-U providesnon-guaranteed delivery of user plane PDUs and supports the followingfunctions: i) Data forwarding, and ii) Flow control. The Xn controlplane interface (Xn-C) is defined between two NG-RAN nodes. Thetransport network layer is built on SCTP on top of IP. The applicationlayer signalling protocol is referred to as XnAP (Xn ApplicationProtocol). The SCTP layer provides the guaranteed delivery ofapplication layer messages. In the transport IP layer point-to-pointtransmission is used to deliver the signalling PDUs. The Xn-C interfacesupports the following functions: i) Xn interface management, ii) UEmobility management, including context transfer and RAN paging, and iii)Dual connectivity.

The NG Interface includes NG User Plane (NG-U) and NG Control Plane(NG-C). The NG user plane interface (NG-U) is defined between the NG-RANnode and the UPF. The transport network layer is built on IP transportand GTP-U is used on top of UDP/IP to carry the user plane PDUs betweenthe NG-RAN node and the UPF. NG-U provides non-guaranteed delivery ofuser plane PDUs between the NG-RAN node and the UPF.

The NG control plane interface (NG-C) is defined between the NG-RAN nodeand the AMF. The transport network layer is built on IP transport. Forthe reliable transport of signalling messages, SCTP is added on top ofIP. The application layer signalling protocol is referred to as NGAP (NGApplication Protocol). The SCTP layer provides guaranteed delivery ofapplication layer messages. In the transport, IP layer point-to-pointtransmission is used to deliver the signalling PDUs.

NG-C provides the following functions: i) NG interface management, ii)UE context management, iii) UE mobility management, iv) ConfigurationTransfer, and v) Warning Message Transmission.

The gNB and ng-eNB host the following functions: i) Functions for RadioResource Management: Radio Bearer Control, Radio Admission Control,Connection Mobility Control, Dynamic allocation of resources to UEs inboth uplink and downlink (scheduling), ii) IP header compression,encryption and integrity protection of data, iii) Selection of an AMF atUE attachment when no routing to an AMF can be determined from theinformation provided by the UE, iv) Routing of User Plane data towardsUPF(s), v) Routing of Control Plane information towards AMF, vi)Connection setup and release, vii) Scheduling and transmission of pagingmessages (originated from the AMF), viii) Scheduling and transmission ofsystem broadcast information (originated from the AMF or O&M), ix)Measurement and measurement reporting configuration for mobility andscheduling, x) Transport level packet marking in the uplink, xi) SessionManagement, xii) Support of Network Slicing, and xiii) QoS Flowmanagement and mapping to data radio bearers. The Access and MobilityManagement Function (AMF) hosts the following main functions: i) NASsignalling termination, ii) NAS signalling security, iii) AS Securitycontrol, iv) Inter CN node signalling for mobility between 3GPP accessnetworks, v) Idle mode UE Reachability (including control and executionof paging retransmission), vi) Registration Area management, vii)Support of intra-system and inter-system mobility, viii) AccessAuthentication, ix) Mobility management control (subscription andpolicies), x) Support of Network Slicing, and xi) SMF selection.

The User Plane Function (UPF) hosts the following main functions: i)Anchor point for Intra-/Inter-RAT mobility (when applicable), ii)External PDU session point of interconnect to Data Network, iii) Packetinspection and User plane part of Policy rule enforcement, iv) Trafficusage reporting, v) Uplink classifier to support routing traffic flowsto a data network, vi) QoS handling for user plane, e.g. packetfiltering, gating, UL/DL rate enforcement, and vii) Uplink Trafficverification (SDF to QoS flow mapping).

The Session Management function (SMF) hosts the following mainfunctions: i) Session Management, ii) UE IP address allocation andmanagement, iii) Selection and control of UP function, iv) Configurestraffic steering at UPF to route traffic to proper destination, v)Control part of policy enforcement and QoS, vi) Downlink DataNotification.

FIG. 5 is a diagram showing a control plane and a user plane of a radiointerface protocol between a UE and a NG-RAN based on a 3rd generationpartnership project (3GPP) radio access network standard.

The user plane protocol stack contains Phy, MAC, RLC, PDCP and SDAP(Service Data Adaptation Protocol) which is newly introduced to support5G QoS model.

The main services and functions of SDAP entity include i) Mappingbetween a QoS flow and a data radio bearer, and ii) Marking QoS flow ID(QFI) in both DL and UL packets. A single protocol entity of SDAP isconfigured for each individual PDU session.

At the reception of an SDAP SDU from upper layer for a QoS flow, thetransmitting SDAP entity may map the SDAP SDU to the default DRB ifthere is no stored QoS flow to DRB mapping rule for the QoS flow. Ifthere is a stored QoS flow to DRB mapping rule for the QoS flow, theSDAP entity may map the SDAP SDU to the DRB according to the stored QoSflow to DRB mapping rule. And the SDAP entity may construct the SDAP PDUand deliver the constructed SDAP PDU to the lower layers.

FIG. 6 is a block diagram of a communication apparatus according to anembodiment of the present invention.

The apparatus shown in FIG. 6 can be a user equipment (UE) and/or eNB orgNB adapted to perform the above mechanism, but it can be any apparatusfor performing the same operation.

As shown in FIG. 6, the apparatus may comprises a DSP/microprocessor(110) and RF module (transmiceiver; 135). The DSP/microprocessor (110)is electrically connected with the transciver (135) and controls it. Theapparatus may further include power management module (105), battery(155), display (115), keypad (120), SIM card (125), memory device (130),speaker (145) and input device (150), based on its implementation anddesigner's choice.

Specifically, FIG. 6 may represent a UE comprising a receiver (135)configured to receive a request message from a network, and atransmitter (135) configured to transmit the transmission or receptiontiming information to the network. These receiver and the transmittercan constitute the transceiver (135). The UE further comprises aprocessor (110) connected to the transceiver (135: receiver andtransmitter).

Also, FIG. 6 may represent a network apparatus comprising a transmitter(135) configured to transmit a request message to a UE and a receiver(135) configured to receive the transmission or reception timinginformation from the UE. These transmitter and receiver may constitutethe transceiver (135). The network further comprises a processor (110)connected to the transmitter and the receiver. This processor (110) maybe configured to calculate latency based on the transmission orreception timing information.

FIG. 7 is a diagram for scheduling request transmission.

The scheduler needs knowledge about the amount of data awaitingtransmission from the terminals to assign the proper amount of uplinkresources. Obviously, there is no need to provide uplink resources to aterminal with no data to transmit as this would only result in theterminal performing padding to fill up the granted resources. Hence, asa minimum, the scheduler needs to know whether the terminal has data totransmit and should be given a grant. This is known as a schedulingrequest.

A scheduling request is a simple flag, raised by the terminal to requestuplink resources from the uplink scheduler. Since the terminalrequesting resources by definition has no PUSCH resource, the schedulingrequest is transmitted on the PUCCH. Each terminal can be assigned adedicated PUCCH scheduling request resource, occurring every nthsubframe. With a dedicated scheduling-request mechanism, there is noneed to provide the identity of the terminal requesting to be scheduledas the identity of the terminal is implicitly known from the resourcesupon which the request is transmitted.

When data with higher priority than already existing in the transmitbuffers arrives at the terminal and the terminal has no grant and hencecannot transmit the data, the terminal transmits a scheduling request atthe next possible instant, as illustrated in FIG. 7. Upon reception ofthe request, the scheduler can assign a grant to the terminal. If theterminal does not receive a scheduling grant until the next possiblescheduling-request instant, then the scheduling request is repeated.There is only a single scheduling-request bit, irrespective of thenumber of uplink component carriers the terminal is capable of. In thecase of carrier aggregation, the scheduling request is transmitted onthe primary component carrier, in line with the general principle ofPUCCH transmission on the primary component carrier only.

The use of a single bit for the scheduling request is motivated by thedesire to keep the uplink overhead small, as a multi-bit schedulingrequest would come at a higher cost. A consequence of the single-bitscheduling request is the limited knowledge at the eNodeB about thebuffer situation at the terminal when receiving such a request.Different scheduler implementations handle this differently. Onepossibility is to assign a small amount of resources to ensure that theterminal can exploit them efficiently without becoming power limited.Once the terminal has started to transmit on the UL-SCH, more detailedinformation about the buffer status and power headroom can be providedthrough the inband MAC control message, as discussed below. Knowledge ofthe service type may also be used—for example, in the case of voice theuplink resource to grant is preferably the size of a typicalvoice-over-IP package. The scheduler may also exploit, for example,path-loss measurements used for mobility and handover decisions toestimate the amount of resources the terminal may efficiently utilize.

An alternative to a dedicated scheduling-request mechanism would be acontention-based design. In such a design, multiple terminals share acommon resource and provide their identity as part of the request. Thisis similar to the design of the random access.

The number of bits transmitted from a terminal as part of a requestwould in this case be larger, with the correspondingly larger need forresources. In contrast, the resources are shared by multiple users.Basically, contention-based designs are suitable for a situation wherethere are a large number of terminals in the cell and the trafficintensity, and hence the scheduling intensity, is low. In situationswith higher intensities, the collision rate between different terminalssimultaneously requesting resources would be too high and lead to aninefficient design.

Although the scheduling-request design for LTE relies on dedicatedresources, a terminal that has not been allocated such resourcesobviously cannot transmit a scheduling request. Instead, terminalswithout scheduling-request resources configured rely on therandom-access mechanism. In principle, an LTE terminal can therefore beconfigured to rely on a contention-based mechanism if this isadvantageous in a specific deployment.

The Scheduling Request (SR) is used for requesting UL-SCH resources fornew transmission. When an SR is triggered, it shall be considered aspending until it is cancelled. All pending SR(s) shall be cancelled andsr-ProhibitTimer shall be stopped when a MAC PDU is assembled and thisPDU includes a BSR which contains buffer status up to (and including)the last event that triggered a BSR, or when the UL grant(s) canaccommodate all pending data available for transmission.

If the Buffer Status reporting procedure determines that at least oneBSR has been triggered and not cancelled and if the MAC entity doesn'thave enough UL resources allocated for new transmission for this TTI(i.e., if an uplink grant is not configured or the Regular BSR was nottriggered due to data becoming available for transmission for a logicalchannel for which logical channel SR masking (logicalChannelSR-Mask) issetup by upper layers), a Scheduling Request shall be triggered.

FIG. 8 is a diagram for signaling of buffer status reporting via a MACCE.

Terminals that already have a valid grant obviously do not need torequest uplink resources. However, to allow the scheduler to determinethe amount of resources to grant to each terminal in future subframes,information about the buffer situation and the power availability isuseful, as discussed above. This information is provided to thescheduler as part of the uplink transmission through MAC controlelement. The LCID field in one of the MAC subheaders is set to areserved value indicating the presence of a buffer status report.

Regarding FIG. 8, Short BSR and Truncated BSR format (a) includes oneLCG ID field and one corresponding Buffer Size field. Long BSR format(b) includes four Buffer Size fields, corresponding to LCG IDs #0through #3. The BSR formats are identified by MAC PDU subheaders withLCIDs as specified in Table 1.

TABLE 1 Index LCID values 00000 CCCH 00001-01010 Identity of the logicalchannel 01011 CCCH 01100-10101 Reserved 10110 Truncated Sidelink BSR10111 Sidelink BSR 11000 Dual Connectivity Power Headroom Report 11001Extended Power Headroom Report 11010 Power Headroom Report 11011 C-RNTI11100 Truncated BSR 11101 Short BSR 11110 Long BSR 11111 Padding

Logical Channel Group ID (LCG ID) field identifies the group of logicalchannel(s) which buffer status is being reported.

The Buffer Size field identifies the total amount of data availableacross all logical channels of a logical channel group after all MACPDUs for the TTI have been built. The amount of data is indicated innumber of bytes. It shall include all data that is available fortransmission in the RLC layer and in the PDCP layer. The size of the RLCand MAC headers are not considered in the buffer size computation.

From a scheduling perspective, buffer information for each logicalchannel is beneficial, although this could result in a significantoverhead. Logical channels are therefore grouped into logical-channelgroups and the reporting is done per group. The buffer-size field in abuffer-status report indicates the amount of data awaiting transmissionacross all logical channels in a logical-channel group.

The Buffer Status Reporting (BSR) procedure is used to provide a servingeNB with information about the amount of data available for transmissionin the UL buffers of the UE. RRC may control BSR reporting byconfiguring the two timers periodicBSR-Timer and retxBSR-Timer and by,for each logical channel, optionally signalling Logical Channel Groupwhich allocates the logical channel to an LCG (Logical Channel Group).

For the Buffer Status reporting procedure, the UE may consider all radiobearers which are not suspended and may consider radio bearers which aresuspended. A Buffer Status Report (BSR) may be triggered if any of thefollowing events occur: i) arrival of data with higher priority thancurrently in the transmission buffer—that is, data in a logical-channelgroup with higher priority than the one currently being transmitted—asthis may impact the scheduling decision, (i.e., UL data, for a logicalchannel which belongs to a LCG, becomes available for transmission inthe RLC entity or in the PDCP entity and either the data belongs to alogical channel with higher priority than the priorities of the logicalchannels which belong to any LCG and for which data is already availablefor transmission, or there is no data available for transmission for anyof the logical channels which belong to a LCG, in which case the BSR isreferred below to as “Regular BSR”; retxBSR-Timer expires and the UE hasdata available for transmission for any of the logical channels whichbelong to a LCG, in which case the BSR is referred below to as “RegularBSR”) ii) change of serving cell, in which case a buffer-status reportis useful to provide the new serving cell with information about thesituation in the terminal, iii) Periodically as controlled by a timer(i.e.,periodicBSR-Timer expires, in which case the BSR is referred belowto as “Periodic BSR”), iv) instead of padding. If the amount of paddingrequired to match the scheduled transport block size is larger than abuffer-status report, a buffer-status report is inserted. Clearly it isbetter to exploit the available payload for useful schedulinginformation instead of padding if possible (i.e., UL resources areallocated and number of padding bits is equal to or larger than the sizeof the Buffer Status Report MAC control element plus its subheader, inwhich case the BSR is referred below to as “Padding BSR”).

For Regular BSR, if the BSR is triggered due to data becoming availablefor transmission for a logical channel for whichlogicalChannelSR-ProhibitTimer is configured by upper layers, if notrunning, the MAC entity starts the logicalChannelSR-ProhibitTimer. Else,if running, the MAC entity stops the logicalChannelSR-ProhibitTimer.

For Regular and Periodic BSR, if more than one LCG has data availablefor transmission in the TTI where the BSR is transmitted, the UE mayreport Long BSR. If else, the UE may report Short BSR.

If the Buffer Status reporting procedure determines that at least oneBSR has been triggered and not cancelled, if the UE has UL resourcesallocated for new transmission for this TTI, the UE may instruct theMultiplexing and Assembly procedure to generate the BSR MAC controlelement(s), start or restart periodicBSR-Timer except when all thegenerated BSRs are Truncated BSRs, and start or restart retxBSR-Timer.

Else if a Regular BSR has been triggered andlogicalChannelSR-ProhibitTimer is not running, if an uplink grant is notconfigured or the Regular BSR was not triggered due to data becomingavailable for transmission for a logical channel for which logicalchannel SR masking (logicalChannelSR-Mask) is setup by upper layers, aScheduling Request shall be triggered.

A MAC PDU may contain at most one BSR MAC control element, even whenmultiple events trigger a BSR by the time a BSR can be transmitted inwhich case the Regular BSR and the Periodic BSR shall have precedenceover the padding BSR.

The MAC entity may restart retxBSR-Timer upon indication of a grant fortransmission of new data on any UL-SCH.

All triggered BSRs may be cancelled in case UL grants in this subframecan accommodate all pending data available for transmission but is notsufficient to additionally accommodate the BSR MAC control element plusits subheader. All triggered BSRs shall be cancelled when a BSR isincluded in a MAC PDU for transmission.

The MAC entity shall transmit at most one Regular/Periodic BSR in a TTLIf the UE is requested to transmit multiple MAC PDUs in a TTI, it mayinclude a padding BSR in any of the MAC PDUs which do not contain aRegular/Periodic BSR.

All BSRs transmitted in a TTI always reflect the buffer status after allMAC PDUs have been built for this TTI. Each LCG shall report at the mostone buffer status value per TTI and this value shall be reported in allBSRs reporting buffer status for this LCG.

FIG. 9 is an example of mapping between logical channel and numerology.

In RAN2 #97bis, RAN2 discussed how to distinguish numerologies in SR.The intention to distinguish numerologies in SR is for the UE to receivean uplink grant with proper numerology that can be used for the datatransmission.

In NR, there will be a mapping between a logical channel and numerology,where different logical channels can be mapped to the same numerologyand one logical channel can be mapped to multiple numerologies.

Normally, the scheduling procedure includes SR, BSR, and datatransmission. If BSR can tell the buffer size per numerology, the UEwill anyway receive an uplink grant with proper numerology. However, itwill take some time to send BSR and then get an uplink grant, whichseems not desirable for URLLC data transmission. Therefore, it would begood to indicate the URLLC data via SR so that the gNB provides anuplink grant with proper numerology for sending URLLC data.

This can be realized by configuring SR resource per logical channel orgroup of logical channels. In specific, when SR is triggered by the datafrom a logical channel, the UE sends SR by using the SR resource for thelogical channel. There is no need to configure separate SR resource forall logical channel but it would be sufficient to configure separate SRresource only for the concerned logical channel.

One may think SR resource can be configured per numerology in order toindicate the numerology of logical channel that triggers SR. However, asone logical channel can be mapped to multiple numerology, the UE mayneed to select only one SR resource, i.e., one numerology. Also,considering that any numerology mapped to the logical channel can beused for sending the data from the logical channel, SR resource pernumerology may not provide sufficient scheduling options to the gNB.

In LTE CA, it is already possible to configure multiple SRs on PCell andPUCCH SCell, but they are treated equally and the UE uses the earliestSR occasion when SR is triggered. LTE DC has the logical channel to cellgroup mapping restrictions for different bearer types, and hence therestrictions of SR triggered by the corresponding logical channel areonly sent to the corresponding cell group. With the agreement of therestriction of logical channel to numerologies/TTI lengths for NR, itshould be straightforward to apply similar restrictions for SRs. Thatis, multiple SR configurations can be configured to the UE and which SRconfiguration is used depends on the LCH that triggers the SR.

If only maximum TTI length is configured as the restriction for logicalchannel to numerology/TTI length mapping, for example, when SR istriggered upon data arrival of a logical channel that can be mapped toonly UL grant of equal to or smaller than 0.5 ms TTI length, the UEshould not send SR on lms PUCCH so that the gNB will only schedule ULgrant of at most 0.5 ms TTI length. If the configuration is not based onmaximum TTI length but with separate configuration of which TTI lengthis usable for each logical channel, the restriction should still beapplicable that SR should not be on the TTI length that is notconfigured to the logical channel which triggered the SR.

On the other hand, with only restriction of SR on allowed TTI length, ifother logical channels that can use UL grant of smaller than lms mayalso send SR on the cells with 0.5 ms TTI length, the gNB would not beable to identify which logical channel(s) triggered the SR, but it canstill follow the restriction of only scheduling UL grant with equal toor smaller than the TTI length where SR was sent. If furtherrestrictions are seen needed for the gNB to better distinguish UL grantof which TTI length is requested by the logical channel (s) triggeredthe SR, the restriction for SR could be only on the maximum allowed TTIlength that the LCH can be mapped to.

For example, it is assumed that LCH1 configured to use TTI length oflms, 0.5 ms and 0.2 ms, and LCH2 configured to use TTI length of 0.5 msand 0.2 ms. And SR is configured on PUCCH of 1 ms and 0.5 ms.

If SR on any allowed TTI length can be used, SR on PUCCH of 0.5 ms wouldnot be able to distinguish the trigger is from data arrival of LCH1 orLCH2, the gNB can schedule 0.5 ms UL grant to be sure. While if only SRon PUCCH of maximum TTI length is used, the gNB could know that the UEis requiring UL grant with TTI length equal to or smaller than 0.5 msbased on the reception of SR on 0.5 ms.

Furthermore, from where the SR is received, the gNB would be able toidentify which logical channel or logical channels with configuredrestrictions has triggered the SR, or in other words knows UL grant ofwhich TTI length is requested and can schedule UL grant accordingly.Thus, there is no need to introduce more bits for SR.

The numerology/TTI type of the logical channel that triggered the SR isindicated through numerology/TTI specific SR resource. Therefore, thereis a one to one mapping between a certain numerology/TTI type and theconfigured SR resource. Reasonably, the corresponding configurationsincluding SR periodicity and SR prohibit timer should be pernumerology/TTI type, detailed analysis is as below:

The QoSs of different logical channels (services) are different. Forexample, URLLC has tighter latency requirement than eMBB. When a URLLCservice triggers a SR, the required UL grant should be mapped to anumerology/TTI type with short latency. On the other side, for eMBBservice, a UL grant with a numerology/TTI type of long latency isenough. The same principle applies to the periodical transmission aswell as prohibition of SR. Recent RAN1 agreement to supportshort-periodicity SR can be used to help meet the UL scheduling latencyrequirements. A SR requiring a UL grant with a numerology/TTI type ofshort latency needs to have shorter SR periodicity and SR prohibit timerthan that requiring a UL grant with a numerology/TTI type of longlatency. Therefore, both SR periodicity and SR prohibit timer should beconfigured for each numerology/TTI type by network.

Meanwhile, RAN2 agreed that multiple SR resource configurations can beconfigured to the UE and which SR resource configuration is used dependson the logical channel that triggers the SR. In other words, SR resourceis configured per logical channel or a group of logical channels. Inspecific, when SR is triggered by the data from a logical channel, theUE sends SR by using the SR resource for the logical channel.

In the prior art, the UE triggers a regular BSR when UL data, for alogical channel which belongs to a logical channel group (LCG), becomesavailable for transmission in the RLC entity or in the PDCP entity andeither the data belongs to a logical channel with higher priority thanthe priorities of the logical channels which belong to any LCG and forwhich data is already available for transmission, or there is no dataavailable for transmission for any of the logical channels which belongto a LCG. If there is no UL resource for transmitting the regular BSR,the UE triggers a SR.

The problem in the prior art is that the UE does not trigger a BSR whena data becomes available for a logical channel that has a lower logicalchannel priority than a logical channel that already data available fortransmission, even if those two logical channels are mapped to differentSR resource.

Considering that different SR resource is used for requesting radioresource for different type of traffics, the BSR trigger mechanismconsidering only logical channel priority should be modified.

If considering that different SR resource is used for requesting radioresource for different type of traffics, the UE needs to trigger a newBSR on a SR resource configuration when a first data becomes availablefor transmission on the SR resource, if a logical channel where the datareceives has lower priority than priorities of other logical channels.And if there is any pending SR on a SR resource configuration, the UEdoesn't need to trigger BSR on the same SR resource configurationanymore to avoid unnecessary waste of resources if the BSR triggersadditional SRs.

FIG. 10 is a conceptual diagram for triggering and transmitting a bufferstatus reporting in wireless communication system according toembodiments of the present invention.

The invention is that when a data becomes available for a logicalchannel (LCH) and if it is the first data of a group of LCHs that aremapped to a same SR resource, the UE triggers a regular BSR.Furthermore, if there is no UL resource for transmitting the regularBSR, the UE triggers a SR that is mapped to the LCH where the databecomes available.

For this, it is assumed that the UE is configured with multiple SRresource configurations and LCH configurations (or RB configurations)(S1001).

It is possible that one or more LCHs are mapped to a SR resource.

Preferably, a group of LCHs that are mapped to a SR resource as a SRgroup. An SR group is mapped to one or more LCHs. An SR group is mappedto one or more logical channel groups (LCGs).

The configuration between multiple SR resource configurations and LCHconfigurations (or RB configurations) is received via RRC signaling. TheUE may receive information of mapping relationship between LCH and SRresource via RRC signaling.

When a data becomes available for a first LCH mapped to the first SRresource configuration, the UE checks whether or not it is a first dataof first SR resource configuration (e.g, a first SR group) to which thefirst LCH is mapped (S1003).

If it is the first data of the first SR group, the UE triggers a regularBSR (S1005).

Preferably, in a state that the first logical channel has a lowerpriority than a highest priority among priorities of logical channels,which are mapped to second SR resource configuration and have data, theUE can trigger a regular BSR on the first SR resource configuration. Inthis case, the first SR resource configuration and the second SRresource configuration are different.

If the regular BSR is triggered by the first LCH, the UE checks whetherthere is available UL resource that can be used for BSR transmission. Ifthere is available UL resource for transmitting the triggered BSR, theUE transmits the regular BSR on the UL resource (S1007). However, ifthere is no available UL resource for transmitting the triggered BSR,the UE triggers a SR that is mapped to the first LCH and transmit it(S1009).

Otherwise, i.e. there is already data available in a second LCH thatbelongs to the SR group, the UE further checks whether the first LCH andsecond LCH belong to a same LCG. If the first LCH and second LCG belongto the same LCG, the UE does not trigger a regular BSR. Or the first LCHand second LCH belong to different LCGs of the SR group, the UE furtherchecks whether the first LCH has higher logical channel priority thanthe second LCH. If the first LCH has higher logical priority than thesecond LCH, the UE triggers a regular BSR. Otherwise, the UE does nottrigger a regular BSR.

Meanwhile, if a data is not the first data on the first SR resourceconfiguration (i.e. there is already data on a logical channel having ahigher priority of the first SR resource configuration), the UE doesn'ttrigger the regular BSR (S1011).

And when second data becomes available for a second LCH mapped to thefirst SR resource configuration after the data becomes available for thefirst LCH, the UE triggers a second BSR, if the second LCH has a higherpriority than a priority of the first LCH.

On the other hand, the UE doesn't trigger a second BSR if there is apending SR on the first SR resource configuration, when the second databecomes available for the second LCH mapped to the first SR resourceconfiguration to avoid unnecessary waste of resources.

FIG. 11 is an example for triggering and transmitting a buffer statusreporting in wireless communication system according to embodiments ofthe present invention

It is assumed that the UE is configured with 9 LCHs (LCH1-LCH9) withcorresponding logical channel priorities (shown as ‘p’ in the figure)and logical channel group (LCG). And the UE is configured with 2 SRresources (SR resource 1 and SR resource 2). In this case the ‘p’corresponding to a lower index has a higher priority.

The UE receives mapping information between LCH and SR resource. TheLCH1-LCH6 are mapped to SR resource 1 (thus, LCH1-LCH6 are called SRgroup 1), and the LCH7-LCH9 are mapped to SR resource 2 (thus, LCH7-LCH9are called SR group 2.

In case that UL resource is not available for any TTIs, when databecomes available in LCH2, as it is the first data of SR group 1, the UEtriggers a regular BSR. As there is no available UL resource fortransmitting the regular BSR, the UE triggers a SR and transmits SR onthe SR resource 1 (step 1).

Later on, a data becomes available in LCH9. As it is the first data ofSR group 2, the UE triggers a regular BSR, even though the logicalchannel priority of LCH9 is lower than that of LCH2 (step 2). As thereis no available UL resource for transmitting the regular BSR, the UEtriggers a SR and transmits SR on the SR resource 2.

Later on, a data becomes available in LCH7. As the LCH7 has higherpriority than the LCH9, and they belong to different LCGs in the SRgroup 2, the UE triggers a regular BSR, even though the logical channelpriority of LCH7 is lower than that of LCH2 (step 3). As there is noavailable UL resource for transmitting the regular BSR, the UE triggersa SR and transmits SR on the SR resource 2.

Alternatively, the UE does not trigger a BSR when data becomes availablein LCH7 when the data becomes available in LCH7 (step 3′). Since a SR isalready triggered on SR resource 2, triggering another SR on the same SRresource is redundant. Thus, triggering a BSR in this case isprohibited.

For this, when the data becomes available for the LCH7, the UE checkswhether it is a first data of a SR group to which the LCH7 belongs. Ifit is the first data of the SR group, the UE triggers a regular BSR.Otherwise, i.e. there is data already available in other LCHs belongingto the SR group, the UE does not trigger a regular BSR.

Or, when the data becomes available for the LCH7, the UE checks whetherthere is any pending SR triggered on the SR resource that is mapped tothe LCH7. If there is a pending SR on the SR resource, the UE does nottrigger a regular BSR. Otherwise, i.e. there is no pending SR on the SRresource, the UE triggers a regular BSR.

The embodiments of the present invention described hereinbelow arecombinations of elements and features of the present invention. Theelements or features may be considered selective unless otherwisementioned. Each element or feature may be practiced without beingcombined with other elements or features. Further, an embodiment of thepresent invention may be constructed by combining parts of the elementsand/or features. Operation orders described in embodiments of thepresent invention may be rearranged. Some constructions of any oneembodiment may be included in another embodiment and may be replacedwith corresponding constructions of another embodiment. It is obvious tothose skilled in the art that claims that are not explicitly cited ineach other in the appended claims may be presented in combination as anembodiment of the present invention or included as a new claim bysubsequent amendment after the application is filed.

In the embodiments of the present invention, a specific operationdescribed as performed by the BS may be performed by an upper node ofthe BS. Namely, it is apparent that, in a network comprised of aplurality of network nodes including a BS, various operations performedfor communication with an MS may be performed by the BS, or networknodes other than the BS. The term ‘eNB’ may be replaced with the term‘fixed station’, ‘Node B’, ‘Base Station (BS)’, ‘access point’, etc.

The above-described embodiments may be implemented by various means, forexample, by hardware, firmware, software, or a combination thereof.

In a hardware configuration, the method according to the embodiments ofthe present invention may be implemented by one or more ApplicationSpecific Integrated Circuits (ASICs), Digital Signal Processors (DSPs),Digital Signal Processing Devices (DSPDs), Programmable Logic Devices(PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers,microcontrollers, or microprocessors.

In a firmware or software configuration, the method according to theembodiments of the present invention may be implemented in the form ofmodules, procedures, functions, etc. performing the above-describedfunctions or operations. Software code may be stored in a memory unitand executed by a processor. The memory unit may be located at theinterior or exterior of the processor and may transmit and receive datato and from the processor via various known means.

Those skilled in the art will appreciate that the present invention maybe carried out in other specific ways than those set forth hereinwithout departing from essential characteristics of the presentinvention. The above embodiments are therefore to be construed in allaspects as illustrative and not restrictive. The scope of the inventionshould be determined by the appended claims, not by the abovedescription, and all changes coming within the meaning of the appendedclaims are intended to be embraced therein.

INDUSTRIAL APPLICABILITY

While the above-described method has been described centering on anexample applied to the 3GPP LTE and NR system, the present invention isapplicable to a variety of wireless communication systems in addition tothe 3GPP LTE and NR system.

The invention claimed is:
 1. A method for a User Equipment (UE)operating in a wireless communication system, the method comprising:configuring a first Schedule Request (SR) resource configuration and asecond SR resource configuration; checking whether data is first data onlogical channels mapped to the first SR resource configuration, when thedata becomes available for a first logical channel mapped to the firstSR resource configuration, wherein the first logical channel has a lowerpriority than a highest priority among priorities of logical channelshaving data, which are mapped to the second SR resource configuration;and triggering a first buffer status reporting (BSR) based on the databeing the first data on logical channels mapped to the first SR resourceconfiguration, triggering a SR for the first SR configuration based onthere being no available UL resource for transmitting the first BSR; andtransmitting the SR to a network, wherein the UE doesn't trigger asecond BSR based on there being a pending SR on the first SR resourceconfiguration, when second data becomes available for a second logicalchannel mapped to the first SR resource configuration, wherein thesecond data becomes available for the second logical channel after thedata becomes available for the first logical channel.
 2. The methodaccording to claim 1, further comprising: transmitting the first BSR tothe network based on there being available an UL resource fortransmitting the first BSR.
 3. The method according to claim 1, furthercomprising: triggering the second BSR when the second data becomesavailable for the second logical channel mapped to the first SR resourceconfiguration, based on the second logical channel having a higherpriority than the priority of the first logical channel.
 4. The methodaccording to claim 1, wherein the UE is capable of communicating with atleast one of another UE, a UE related to an autonomous driving vehicle,a base station and a network.
 5. A User Equipment (UE) for operating ina wireless communication system, the UE comprising: transmitter and areceiver; and a processor operably coupled with the transmitter andreceiver and configured to: configure a first Schedule Request (SR)resource configuration and a second SR resource configuration, checkwhether data is first data on logical channels mapped to the first SRresource configuration, when the data becomes available for a firstlogical channel mapped to the first SR resource configuration, whereinthe first logical channel has a lower priority than a highest priorityamong priorities of logical channels having data, which are mapped tothe second SR resource configuration, and trigger a first buffer statusreporting (BSR) based on the data being the first data on logicalchannels mapped to the first SR resource configuration, trigger a SR forthe first SR for the first SR configuration based on there being noavailable UL resource for transmitting the first BSR, and transmit theSR to a network, wherein the UE doesn't trigger a second BSR based onthere being a pending SR on the first SR resource configuration, whensecond data becomes available for a second logical channel mapped to thefirst SR resource configuration, wherein the second data becomesavailable for the second logical channel after the data becomesavailable for the first logical channel.
 6. The UE according to claim 5,wherein the processor is further configured to: transmit the first BSRto the network based on there being available an UL resource fortransmitting the first BSR.
 7. The UE according to claim 5, wherein theprocessor is further configured to: trigger the second BSR when thesecond data becomes available for the second logical channel mapped tothe first SR resource configuration, based on the second logical channelhaving a higher priority than the priority of the first logical channel.8. The UE according to claim 5, wherein the UE is capable ofcommunicating with at least one of another UE, a UE related to anautonomous driving vehicle, a base station and a network.